$6.(1$ point$)$ We are using AES in counter mode to encrypt a hard disk with $1$ TB of capacity. The counter, ctr$,$ can be many numbers. Consider the binary representation of ctr$.$ What is the maximum possible lenght of the binary representation of ctr$?$ Hint: how many blocks, $128$ bits each, do you need? Let's say it is n $.$ Then you will need to use $\backslash (\backslash$operatorname$\{$ctr$\}+1,\backslash$operatorname$\{$ctr$\}+2,\backslash$ldots$,\backslash$mathrm$\{$ctr$\}+\backslash$mathrm$\{$n$\}\backslash )$ as the inputs to AES instances for blocks. So what can be the maximum lenght for the ctr that you choose?